Which of the following transitions involves the maximum amount of energy?

The ionization potentials of $Li$ and $K$ are $5.4 \ eV$ and $4.3 \ eV$ respectively. The ionization potential of $Na$ will be .............. $eV$.

The first and second ionisation enthalpies of a metal are $496$ and $4560 \; kJ \; mol^{-1},$ respectively. How many moles of $HCl$ and $H_{2}SO_{4}$ respectively,will be needed to react completely with $1$ mole of the metal hydroxide?

The second ionization potential of $Li$,$Be$,and $B$ is in the order:

The electronic configurations of elements $A, B$ and $C$ are $[He] 2s^1$,$[Ne] 3s^1$ and $[Ar] 4s^1$ respectively. Which one of the following orders is correct for the first ionization potentials (in $kJ \ mol^{-1}$) of $A, B$ and $C$?

The first ionization enthalpies of $Mg$ and $Al$ can be expected to be